OBJECTIVE: Studying gender differences in fat mass and distribution in a homogeneous group of children. DESIGN: Crosssectional study. SUBJECTS: 610 children aged 5 ± 7 y in Kiel, Germany. METHODS: Anthropometric measures, bioelectrical impedance analysis (BIA). RESULTS: Although boys had increased body weights (P`0.05), body mass indexes (BMI's) (P`0.001) and waistahip ratios (WHRs) (P`0.001), the %fat mass as assessed by BIA (P`0.05) was increased in girls. Although the increased BMI in boys was independent of the percentile used, gender differences (that is, lower values for boys than for girls at the same age) in WHR, the sum of four skinfolds and %fat were seen up to the 90th percentile. By contrast, above the 90th percentile there were no differences in skinfold thickness and %fat between boys and girls. Studying 42 BMImatched pairs (boys and girls) also showed that the %fat estimated by BIA (P`0.001) was increased in girls. Plotting the average of %fat as obtained from skinfold-and BAI-measurements against the difference between data obtained by the use of the two methods shows that BIA %fat overestimates skinfold %fat at low or normal percent fat mass (that is, up to 20%) in both genders. By contrast, at increased fat mass, BIA %fat seems to underestimate skinfold %fat in both genders. CONCLUSIONS: Gender differences in fat mass and fat distribution are obvious in children aged 5 ± 7 y. These differences are independent of gender differences in body weight. However, the nutritional state has an in¯uence and gender differences cannot be detected in overweight and obese children. Our data also suggest that a childrenspeci®c formula used to calculate %fat from skinfold measurements is inappropriate.

Substantial dietary underreporting questions the validity of dietary measurements of energy intake (El). The present study compares the value of a 7-day prospective dietary record (7dDR) with a computer program-based diet history (DH). 7dDR and DH were performed in 50 non-obese subjects (33 females, 17 males, mean age 26.1 years, BMI 18.9-29.6 kg/ m2) using total energy expenditure (EE = sum of resting metabolic rate as measured by indirect calorimetry plus energy expenditure derived from an activity protocol) as standard for the validity of data on EL El was 2,206 (728-3,646) kcal/day for 7dDR and 2,398 (566-4,764) kcal/day for DH. There was an association between El for 7dDR and El for DH (r = 0.6, p < 0.0001). Underreporting [i.e. a difference between El and EE (ΔE = EI-EE)] of 20% or more was seen in 48% (7dDR, mean -1,047 kcal/day, range -616 to -1,895, or -38.8% of EE) or 48% (DH, -1,151 kcal/day, -594 to -2,057 kcal/day, or -42.3% of EE). Considerable differences were found between ΔE for 7dDR and ΔE for DH (mean 603, range 26-2,033 kcal/ day), and only 34% of underreporting subjects were identified by both dietary measurements. It is concluded that at the individual level dietary underreporting is influenced by the dietary assessment tool.

There are wide socio-economic differences in choice of snack foods between children from Germany and England.